Let's keep it simple -- which non-Universalist nation has ever been willing to allow as much relative influence to Jewish people as Universalist systems have?

You've got to make it more general, that's where it gets interesting! Speaking frankly, from the selfish viewpoint of a typical Western person, the Universalist system has been better than any other system at everything for more than a century, especially at the quality and complexity of life for the average citizen. Of course, Moldbug's adherents would argue that there's no dependency between these two unique, never-before-seen facts of civilization - universalist ideology and an explosive growth in human development for the bottom 90% of society. They'd say that both are symptoms of more rapid and thoroughly supported technological progress than elsewhere.

Let's concede that (although there are reasons to challenge it - see e.g. Weber's The Protestant Ethic and the Spirit of Capitalism, an early argument that religion morphing into a secular quasi-theocracy is what gave the West its edge). Okay, so if both things are the results of our civilization's unique historical path... then, from an utilitarian POV, the cost of universalism is still easily worth paying! We know of no society that advanced to an industrial and then post-industrial state without universailsm, so it would be in practice impossible to alter any feature of technical and social change to exclude the dominance of universalist ideology but keep the pace of "good" progress. Then, even assuming that universalist ideology is single-handedly responsible for the entirety of the 20th century's wars and mass murder (and other evils), it is still preferable to the accumulated daily misery of the traditional pre-industrial civilization - especially so for everyone who voted "Torture" on "Torture vs Specks"! (I didn't, but here I feel differently, because it's "Horrible torture and murder" vs "Lots and lots of average torture".)